1. Field of the Invention
This invention relates to a lens module, more particularly to a lens module having two lens units respectively defining light communicating paths.
2. Description of the Related Art
Referring to FIGS. 1 and 2, currently, to determine the coordinate position of an object in a three dimensional space, at least two spaced-apart image capturing devices 1, 1′ are required to perform an image capturing operation. Both of the two image capturing devices 1, 1′ are simultaneously assembled on an electronic device (not shown). Each image capturing device 1, 1′ includes a base 11, a lens unit 12 fixed within the base 11, a circuit board 13 welded to a bottom end of the base 11, and a sensor element 14 provided on a top face of the circuit board 13 and spaced apart from and disposed below the lens unit 12. Two intersecting lines (A) passing through the lens unit 12 of the image capturing device 1 define therebetween a viewable region (A1) of the image capturing device 1. Two intersecting lines (B) passing through the lens unit 12 of the image capturing device 1′ define therebetween a viewable region (B1) of the image capturing device 1′. An image of an object 2 located on an overlapping region (C) of the viewable regions (A1, B1) is simultaneously formed on the sensor elements 14 of the two image capturing devices 1, 1′.
For example, when the object 2 moves from a first position (D1) to a second position (D2), or from the second position (D2) to a third position (D3), the position of the image of the object 2 formed on the sensor elements 14 through the respective lens units 12 is varied. The sensor elements 14 of the two image capturing devices 1, 1′ can transmit the captured image data to a computing unit (not shown) of the electronic device through the circuit board 13 so as to differentiate between the coordinate position and the change in the coordinate position of the object 2 in three dimensional space.
Since the image capturing devices 1, 1′ have to be separately manufactured, after which they are assembled on the electronic device, the assembly process thereof is time-consuming, and the manufacturing cost thereof is high. Further, the electronic device must provide a large space to accommodate assembly of the two image capturing devices 1, 1′. Moreover, the components of each image capturing device 1, 1′ have specific assembly tolerances during assembly, so that accuracy between the lens units 12 of the two image capturing devices 1, 1′ after their assembly on the electronic device cannot be easily controlled.